In order to cast a part having a number of closely spaced protrusions with relatively large aspect ratios, such as a pin-type heat sink, it is typically necessary to have an ejector pin for each such protrusion. Having a large number of closely spaced ejector pins, each with a relatively small cross-sectional area, is problematic for a number of reasons. It is difficult to properly lubricate such pins, which increases the likelihood of pin binding and pin wear, which itself leads to problems. More maintenance time is required to repair and replace the pins. Also, since the pins contact the die cavity, they wear fairly quickly, and they also wear the die cavity, leading to the creation of flashing on the cast parts, which increases the need for costly rework. This also leads to increased down-time for pin and tool repair and replacement.